Access non-numeric Object properties by index?

Question

If I have an array like this:

var arr = [\'one\',\'two\',\'three\'];

I can access different parts by doing this:

console.lo         


        

Answer 1

The only way I can think of doing this is by creating a method that gives you the property using Object.keys();.

var obj = {
    dog: "woof",
    cat: "meow",
    key: function(n) {
        return this[Object.keys(this)[n]];
    }
};
obj.key(1); // "meow"

Demo: http://jsfiddle.net/UmkVn/

It would be possible to extend this to all objects using Object.prototype; but that isn't usually recommended.

Instead, use a function helper:

var object = {
  key: function(n) {
    return this[ Object.keys(this)[n] ];
  }
};

function key(obj, idx) {
  return object.key.call(obj, idx);
}

key({ a: 6 }, 0); // 6

Answer 2

Get the array of keys, reverse it, then run your loop

  var keys = Object.keys( obj ).reverse();
  for(var i = 0; i < keys.length; i++){
    var key = keys[i];
    var value = obj[key];
    //do stuff backwards
  }

Answer 3

"I'm specifically looking to target the index, just like the first example - if it's possible."

No, it isn't possible.

The closest you can get is to get an Array of the object's keys, and use that:

var keys = Object.keys( obj );

...but there's no guarantee that the keys will be returned in the order you defined. So it could end up looking like:

keys[ 0 ];  // 'evenmore'
keys[ 1 ];  // 'something'

Answer 4

var obj = {
    'key1':'value',
    '2':'value',
    'key 1':'value'
}

console.log(obj.key1)
console.log(obj['key1'])
console.log(obj['2'])
console.log(obj['key 1'])

// will not work
console.log(obj.2)

Edit:

"I'm specifically looking to target the index, just like the first example - if it's possible."

Actually the 'index' is the key. If you want to store the position of a key you need to create a custom object to handle this.

Answer 5

If you are not sure Object.keys() is going to return you the keys in the right order, you can try this logic instead

var keys = []
var obj = {
    'key1' : 'value1',
    'key2' : 'value2',
    'key3' : 'value3',
}
for (var key in obj){
    keys.push(key)
}
console.log(obj[keys[1]])
console.log(obj[keys[2]])
console.log(obj[keys[3]])

Answer 6

You can use the Object.values() method if you dont want to use the Object.keys().

As opposed to the Object.keys() method that returns an array of a given object's own enumerable properties, so for instance:

const object1 = {
 a: 'somestring',
 b: 42,
 c: false
};

console.log(Object.keys(object1));

Would print out the following array:

[ 'a', 'b', 'c' ]

The Object.values() method returns an array of a given object's own enumerable property values.

So if you have the same object but use values instead,

const object1 = {
 a: 'somestring',
 b: 42,
 c: false
};

console.log(Object.values(object1));

You would get the following array:

[ 'somestring', 42, false ]

So if you wanted to access the object1.b, but using an index instead you could use:

Object.values(object1)[1] === 42

You can read more about this method here.